1. Field of the Invention
This invention relates to pressure transducers and in particular to a transducer for measuring gaseous pressure differential across a chamber wall. The pressure transducer described has particular application in air cleaning systems.
2. Description of Prior Art
A common form of air cleaning system forces dust-laden air through filter bags fabricated from a material such that dust intended to be removed builds up on one surface of each bag. A multiplicity of bags may be used together in parallel and suspended from apertures in a dividing wall or cell plate within a purpose-designed vessel. Such a system is known as a "baghouse".
It is known to monitor the pressure differential across the filter bags to provide an indication of the state of the filter bags and thus initiate manual or automatic bag cleaning. The pressure differential arises due to frictional and kinetic energy losses through each bag. Conventional systems use a water manometer with sensing tubes connected into the vessel either side of the cell plate. Electronic pressure transducers have also been proposed but, as with the U-tube manometer, require coupling hoses and sensing ports open to the interior of the cell.
These conventional pressure indicators suffer from the disadvantage that the transducer connection on the dusty air side of the cell fills with contaminants to cause erroneous pressure differential readings. Clogged manometer ports either give a false indication of dust build-up on the filter bags, or cause early indications of filter problems to be missed.
3. Identification of Object of the Invention
It is therefore an object of the present invention to provide a gaseous pressure transducer which will at least go some way towards overcoming the above mentioned disadvantage or which will at least provide the industry with a useful choice.